forkkmuopengl/BaseGLProject/MyGLWindow.cpp

#include <direct.h>
#include "MyGlWindow.h"
//Getting the projection matrix
glm::mat4x4 perspective(float fovy, float aspect, float near, float far)
{
	float fovy2 = glm::tan(fovy / 2);

	glm::mat4x4 pmat{ { 1 / (aspect * fovy2), 0, 0, 0},
					  { 0, 1 / fovy2, 0, 0},
					  { 0, 0, -((far + near) / (far - near)), -1},
					  { 0, 0, -((2 * far * near) / (far - near)), 0} };


	return pmat;
}

// Getting the view matrix
glm::mat4x4 lookAt(glm::vec3 campos, glm::vec3 look, glm::vec3 up)
{
	glm::vec3 ZCam(glm::normalize(campos - look));
	glm::vec3 XCam(glm::normalize(glm::cross(up, ZCam)));
	glm::vec3 YCam(glm::normalize(glm::cross(ZCam, XCam)));

	glm::mat4x4 cam_mat{ {XCam.x, YCam.x, ZCam.x, 0},
						 {XCam.y, YCam.y, ZCam.y, 0},
						 {XCam.z, YCam.z, ZCam.z, 0},
						 {0, 0, 0 ,1} };

	glm::mat4x4 norm_mat{ {1, 0, 0, 0},
						  {0, 1, 0, 0},
						  {0, 0, 1, 0},
						  {-campos.x, -campos.y, -campos.z, 1} };

	return cam_mat * norm_mat;
}


MyGlWindow::MyGlWindow(int w, int h) : 
	viewer(glm::vec3(5, 5, 5), glm::vec3(0, 0, 0), glm::vec3(0, 1, 0), 45.0f, (w / (float)h))
{
	m_width = w;
	m_height = h;

	setup();
}

MyGlWindow::~MyGlWindow()
{	
}

void MyGlWindow::setBgColor(float bgColor[3])
{
	_bgColor[0] = bgColor[0];
	_bgColor[1] = bgColor[1];
	_bgColor[2] = bgColor[2];
}

void MyGlWindow::textureSetup()
{
	glActiveTexture(GL_TEXTURE0);
	glGenTextures(1, &_scnctx.textures);  //tex_2d is a member variable
	glBindTexture(GL_TEXTURE_2D, _scnctx.textures);

	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT);

	int width, height, channel;
	unsigned char * image = stbi_load("brick1.jpg", &width, &height, &channel, 0);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB,
		GL_UNSIGNED_BYTE, image);
	glGenerateMipmap(GL_TEXTURE_2D);

	stbi_image_free(image);
	glBindTexture(GL_TEXTURE_2D, 0);
}

void MyGlWindow::shaderSetup()
{
	shaders["Simple"] = new Shader("simple.vert", "simple.frag");
	shaders["Simple"]->uniformFlags = ShaderFlags::MVP_FLAG;

	shaders["BaseLight"] = new Shader("base_light.vert", "base_light.frag");
	shaders["Fog"] = new Shader("fog.vert", "fog.frag");

	shaders["TexBaseLight"] = new Shader("tex_base_light.vert", "tex_base_light.frag");
	shaders["TexBaseLight"]->addUniform("tex1", 0);

	shaders["SpotLight"] = new Shader("spotlight.vert", "spotlight.frag");
	shaders["SpotLight"]->light_type = Light::LightType::SPOT;
	shaders["TexSpotLight"] = new Shader("tex_spotlight.vert", "tex_spotlight.frag");
	shaders["TexSpotLight"]->light_type = Light::LightType::SPOT;


	shaders["Silhouette"] = new Shader("silhouette.vert", "silhouette.frag");
	shaders["Silhouette"]->uniformFlags = ShaderFlags::MVP_FLAG;
	shaders["Silhouette"]->addUniform("fColor", glm::vec3(237 / 255, 229 / 255, 194 / 255));
	shaders["Silhouette"]->addUniform("sil_offset", 0.1f);

	shaders["Toon"] = new Shader("base_light.vert", "toon.frag");
	//Removing useless specular component
	shaders["Toon"]->uniformFlags &= ~ShaderFlags::KS_FLAG;
	shaders["Toon"]->uniformFlags &= ~ShaderFlags::SHINE_FLAG;
}

void MyGlWindow::lightSetup()
{
	//Showcase lights
	_scnctx.lights.emplace("Light1", Light(glm::vec3(0.8f), glm::vec4(3, 10, 5, 1)));

	//Party lights
	/*_scnctx.lights.emplace("Light1", Light(glm::vec3(0.0f, 0.5f, 0.5f), glm::vec4(10, 10, 0, 1)));
	_scnctx.lights.emplace("Light2", Light(glm::vec3(0.0f, 0.0f, 0.5f), glm::vec4(3.09, 10, 9.51, 1)));
	_scnctx.lights.emplace("Light3", Light(glm::vec3(0.5f, 0.0f, 0.0f), glm::vec4(-8.09, 10, 5.87, 1)));
	_scnctx.lights.emplace("Light4", Light(glm::vec3(0.0f, 0.5f, 0.0f), glm::vec4(-8.09, 10, -5.87, 1)));
	_scnctx.lights.emplace("Light5", Light(glm::vec3(0.5f, 0.5f, 0.5f), glm::vec4(3.09, 10, -9.51, 1)));*/
}

void MyGlWindow::setup()
{	
	textureSetup();
	shaderSetup();
	lightSetup();
	
	Dataset moddata;
	moddata.checkeredFloor(20, 20, glm::vec3(0.1, 0.1, 0.1), glm::vec3(0.7, 0.7, 0.7));
	meshes.push_back(new Mesh(moddata, shaders["Simple"]));
	meshes.back()->addTranslation(glm::vec4(0, -0.05, 0, 1));
	meshes.back()->cullMode = BACK;

	moddata.simpleCube();	
	meshes.push_back(new Mesh(moddata, shaders["TexBaseLight"]));	
	meshes.back()->addTranslation(glm::vec4(0, 1, 0, 1));

	moddata.sphere(1, 100, 100);
	meshes.push_back(new Mesh(moddata, shaders["BaseLight"]));
	meshes.back()->addTranslation(glm::vec4(-5, 1, -3, 1));

	meshes.push_back(new Mesh("teapot.obj", shaders["Silhouette"]));
	meshes.back()->addTranslation(glm::vec4(5, 0 ,3, 1));
	meshes.back()->cullMode = FRONT;	
	meshes.push_back(new Mesh("teapot.obj", shaders["Toon"]));
	meshes.back()->addTranslation(glm::vec4(5, 0, 3, 1));
	meshes.back()->cullMode = BACK;
	
}

void MyGlWindow::draw()
{	
	glClearColor(_bgColor[0], _bgColor[1], _bgColor[2], 1);	
	glViewport(0, 0, m_width, m_height);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_DEPTH_BUFFER);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glm::vec3 eye(viewer.getViewPoint().x, viewer.getViewPoint().y, viewer.getViewPoint().z);
	glm::vec3 look(viewer.getViewCenter().x, viewer.getViewCenter().y, viewer.getViewCenter().z);
	glm::vec3 up(viewer.getUpVector().x, viewer.getUpVector().y, viewer.getUpVector().z);
	glm::mat4 view = lookAt(eye, look, up);   //Calculate view matrix from parameters of m_viewer
	glm::mat4 projection = perspective(45.0f, (float)m_width / (float)m_height, 0.1f, 500.0f);
	
	_scnctx.viewMatrix = view;
	_scnctx.projectionMatrix = projection;
	for (auto it = meshes.begin(); it != meshes.end(); it++)
		(*it)->draw(_scnctx);
}

void MyGlWindow::resize(int w, int h)
{
	m_width = w;
	m_height = h;
	viewer.setAspectRatio(w / float(h));
}